rethinkdb-regrid
A file storage system for RethinkDB inspired by GridFS
Last updated a month ago by internalfx .
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ReGrid

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ReGrid is a method of storing large files inside a RethinkDB database.

Features

  • Reliable - Files are replicated across the cluster, benefiting from RethinkDB's automatic failover.
  • Scalable - Easily store large files in RethinkDB, distributed across the cluster.
  • Consistent - Sha256 hashes are calculated when the file is written, and verified when read back out.
  • Realtime - Watch the file system for changes and be notified immediately.
  • Fast - Supports in-memory caching so your server doesn't fall over when something goes viral.
  • Current - Uses RethinkDB's changefeeds to evict cached items. ReGrid doesn't serve stale files.

View the Changelog

The ReGrid spec is an open specification free for anyone to implement and use.

The spec is very out of date

Need help?

Join Slack here, then meet us on the #regrid channel.

Join Slack


Special thanks to Arthur Andrew Medical for sponsoring this project.

Arthur Andrew Medical manufactures products with ingredients that have extensive clinical research for safety and efficacy. We specialize in Enzymes, Probiotics and Antioxidants.


Installation

Supports node v8.0+

npm install --save rethinkdb-regrid

TL;DR

var ReGrid = require('rethinkdb-regrid')

var bucket = ReGrid({db: 'example'})

// initBucket creates tables and indexes if they don't exist, returns a promise.
bucket.initBucket().then(function () {
  // We are now ready to read and write files

  // Watch a filename for changes
  bucket.watchFilename('/videos/myVid.mp4').then(function (cursor) {
    cursor.each((err, changes) => {
      console.log(changes)
    })
  })

  // Open a write stream to ReGrid
  var dbStream = bucket.upload('/videos/bigvid.mp4')

  // Create read stream from file and pipe it to a ReGrid write stream
  fs.createReadStream('./bigvid.mp4').pipe(dbStream)

  dbStream.on('finish', function () {
    // File is now written to the database

    //Read the file and pipe it to a write stream to save the file back out to the file system.
    bucket.downloadFilename('/videos/bigvid.mp4').pipe(fs.createWriteStream('./copy-of-bigvid.mp4'))
  })

})

API Documentation

ReGrid([connectionOptions, options])

Parameters
key default type description
connectionOptions {} Object connectionOptions is passed directly to rethinkdbdash
options {} Object Optional parameters listed below
Options
key default type description
bucketName fs String The name of the bucket. Table names are prefixed by this.
chunkSizeBytes 1024 * 255 Number The default chunk size, in bytes.
concurrency 10 Number When writing/reading a file, the number of concurrent queries in flight for a given stream.
cacheSize 400 Number The maximum number of objects to keep in memory. Setting to 0 will disable caching.
returns

Bucket instance

Description

Creates a new ReGrid bucket instance.

Example
var ReGrid = require('rethinkdb-regrid')

var bucket = ReGrid({db: 'mydatabase'}, {bucketName: 'mybucket'})

initBucket()

Parameters

none

returns

Promise

Description

Verifies required tables and indexes exist and will create them if missing.

Example
bucket.initBucket().then(function () {
  // bucket is ready for use.....
})

writeFile(options)

Options
key default type description
filename required String The name of the file.
buffer required Buffer A buffer of file contents.
chunkSizeBytes The chunkSizeBytes setting for the bucket. Number Size of each chunk in bytes.
metadata {} Object Metadata object allowing you to store custom keys on files.
returns

Promise

Description

Returns a promise that resolves to the newly written file.

Example
let fileBuffer = fs.readFileSync('./myVid.mp4')

let newFile = await bucket.writeFile({filename: '/videos/myVid.mp4', buffer: fileBuffer})

createWriteStream(options)

Options
key default type description
filename required String The name of the file.
chunkSizeBytes The chunkSizeBytes setting for the bucket. Number Size of each chunk in bytes.
metadata {} Object Metadata object allowing you to store custom keys on files.
returns

WriteStream

Description

Returns a write stream for storing a file in ReGrid.

Example
var writeStream = bucket.createWriteStream({
  filename: '/videos/myVid.mp4',
  chunkSizeBytes: 1024 * 255,
  metadata: {topic: 'cats'}
})

writeStream.on('finish', function () {
  // File is now stored in ReGrid
})

fs.createReadStream('./myVid.mp4').pipe(writeStream)

getFile(options)

Options
key default type description
id Null String The id of the file to retrieve.
filename Null String Ignored if id != null. The filename of the file to retrieve
revision -1 Number Ignored if id != null. The revision of the file to retrieve. If multiple files are uploaded under the same filename they are considered revisions. This may be a positive or negative number. (see chart below)
How revision numbers work

If there are five versions of a file, the below chart would be the revision numbers

Number Description
0 or -5 The original file
1 or -4 The first revision
2 or -3 The second revision
3 or -2 The second most recent revision
4 or -1 The most recent revision
Description

Returns a promise that resolves to the files information.

Example
let file1 = bucket.getFile({id: 'ca608825-15c0-44b5-9bef-3ccabf061bab'})
let file2 = bucket.getFile({filename: 'catVideo.mp4', revision: 2})

readFile(options)

Options
key default type description
id Null String The id of the file to retrieve.
filename Null String Ignored if id != null. The filename of the file to retrieve
revision -1 Number Ignored if id != null. The revision of the file to retrieve. If multiple files are uploaded under the same filename they are considered revisions. This may be a positive or negative number. (see chart below)
seekStart Null Number The start of the byte range.
seekEnd Null Number The end of the byte range. If omitted the stream will continue to the end of file.
How revision numbers work

If there are five versions of a file, the below chart would be the revision numbers

Number Description
0 or -5 The original file
1 or -4 The first revision
2 or -3 The second revision
3 or -2 The second most recent revision
4 or -1 The most recent revision
Description

Returns a promise that resolves to the files information and contents.

Example
let file1 = bucket.readFile({id: 'ca608825-15c0-44b5-9bef-3ccabf061bab'})
let file2 = bucket.readFile({filename: 'catVideo.mp4', revision: 2})

createReadStream(options)

Options
key default type description
id required String The id of the file to retrieve
seekStart Null Number The start of the byte range.
seekEnd Null Number The end of the byte range. If omitted the stream will continue to the end of file.
returns

ReadStream

Description

Returns a read stream for reading a file from ReGrid.

Example
var readStream = bucket.createReadStream({id: 'ca608825-15c0-44b5-9bef-3ccabf061bab'})

readStream.pipe(fs.createWriteStream('./mySavedVideo.mp4'))

downloadFilename(filename[, options])

Parameters
key default type description
filename required String The name of the file.
options {} Object Optional parameters listed below
Options
key default type description
revision -1 Number The revision of the file to retrieve. If multiple files are uploaded under the same filename they are considered revisions. This may be a positive or negative number. (see chart below)
seekStart Null Number The start of the byte range.
seekEnd Null Number The end of the byte range. If omitted the stream will continue to the end of file.
How revision numbers work

If there are five versions of a file, the below chart would be the revision numbers

Number Description
0 or -5 The original file
1 or -4 The first revision
2 or -3 The second revision
3 or -2 The second most recent revision
4 or -1 The most recent revision
returns

ReadStream

Description

Returns a read stream for reading a file from ReGrid.

Example
var newestVersion = bucket.downloadFilename('/videos/myVid.mp4')

var originalVersion = bucket.downloadFilename('/videos/myVid.mp4', {revision: 0})

newestVersion.pipe(fs.createWriteStream('./latest.mp4'))

originalVersion.pipe(fs.createWriteStream('./original.mp4'))

getFilename(filename[, options])

Parameters
key default type description
filename required String The name of the file.
options {} Object Optional parameters listed below
Options
key default type description
revision -1 Number The revision of the file to retrieve. If multiple files are uploaded under the same filename they are considered revisions. This may be a positive or negative number. (see chart below)
How revision numbers work

If there are five versions of a file, the below chart would be the revision numbers

Number Description
0 or -5 The original file
1 or -4 The first revision
2 or -3 The second revision
3 or -2 The second most recent revision
4 or -1 The most recent revision
returns

Promise that resolves to the files information.

Description

Returns information for a file from ReGrid.

Example
bucket.getFilename('/videos/myVid.mp4', {revision: 0}).then(function (file) {
  console.log(file)

  /*
  RETURNS
  {
    "chunkSizeBytes": 261120 ,
    "filename":  "/videos/myVid.mp4" ,
    "finishedAt": Wed Jan 11 2017 20:35:20 GMT+00:00 ,
    "id":  "2578d295-6041-40e6-9235-d02e96c524ca" ,
    "length": 174110 ,
    "sha256":  "298fac8be0bdb1e48fa520dee5f510ef5f91ea0411b7584e8c62ec0cf34ce932" ,
    "startedAt": Wed Jan 11 2017 20:35:20 GMT+00:00 ,
    "status":  "Complete"
  }
  */
})

listRegex(pattern[, options])

Parameters
key default type description
pattern required String A regular expression matched against filename
options {} Object Optional parameters listed below
Options
key default type description
sort 'DESC' String Sort results by filename. Valid values are ASC and DESC.
skip undefined Number Skip results, useful for pagination.
limit undefined Number Limit results.
showAll false Boolean Show all revisions of matched files. Normally duplicate filenames are hidden and only the latest revision of each filename is returned.
returns

ReadStream in objectMode. The stream emits objects, not buffers.

Description

Returns a read stream for finding files via regular expression. The stream emits objects as they are found, and can be a long running operation.

You may call toArray() on the returned stream to coerce it to an array. This may fail if the result set is very large. You may optionally call with limit to prevent this.

Example
var videoStream = bucket.listRegex('^/videos/', {limit: 100})

videoStream.on('data', function (video) {
  console.log(video)
})

// OR
bucket.listRegex('^/videos/', {limit: 100}).toArray().then(function (videos) {
  // list the first 100 videos in the `/videos` directory
  console.log(videos)
})

listFilename(filename[, options])

Parameters
key default type description
filename required String The name of the file.
options {} Object Optional parameters listed below
Options
key default type description
sort undefined String Sort results by finishedAt (The date the file was uploaded). Valid values are ASC and DESC.
skip undefined Number Skip results, useful for pagination.
limit undefined Number Limit results.
returns

ReadStream in objectMode. The stream emits objects, not buffers.

Description

Returns a read stream for finding files by filename. The stream emits objects as they are found, and can be a long running operation. However, this method uses an index and is very efficient.

You may call toArray() on the returned stream to coerce it to an array. This may fail if the result set is very large. You may optionally call with limit to prevent this.

Example
var revisionStream = bucket.listFilename('/videos/editedVideo.mp4')

revisionStream.on('data', function (revision) {
  console.log(revision)
})

// OR
bucket.listFilename('/videos/editedVideo.mp4').toArray().then(function (revisions) {
  // list all revisions of '/videos/editedVideo.mp4'
  console.log(revisions)
})

listMetadata(metadata[, options])

Parameters
key default type description
metadata required Object An object to match against the metadata field of ReGrid files.
options {} Object Optional parameters listed below
Options
key default type description
skip undefined Number Skip results, useful for pagination.
limit undefined Number Limit results.
returns

ReadStream in objectMode. The stream emits objects, not buffers.

Description

Returns a read stream for finding files by metadata. The stream emits objects as they are found, and can be a long running operation.

You may call toArray() on the returned stream to coerce it to an array. This may fail if the result set is very large. You may optionally call with limit to prevent this.

Example
var catStream = bucket.listMetadata({topic: 'cats'})

catStream.on('data', function (catVideo) {
  console.log(catVideo)
})

// OR
bucket.listMetadata({topic: 'cats'}).toArray().then(function (catVideos) {
  // list all videos under the 'cat' topic.
  console.log(catVideos)
})

watchRegex(pattern)

Parameters
key default type description
pattern required String A regular expression matched against filename.
returns

A RethinkDB changeFeed cursor

Description

Allows you to be notified of changes to a file if the filename property matches your regular expression.

Example
bucket.watchRegex('^/videos').then(function (cursor) {
  cursor.each((err, video) => {
    console.log(video)
  })
})

watchFilename(filename)

Parameters
key default type description
filename required String The filename to watch for changes.
returns

A RethinkDB changeFeed cursor

Description

Allows you to be notified of changes to a file if the filename property === your string.

Example
bucket.watchFilename('/videos/myVid.mp4').then(function (cursor) {
  cursor.each((err, changes) => {
    console.log(changes)
  })
})

watchMetadata(metadata)

Parameters
key default type description
metadata required Object The metadata to watch for changes.
returns

A RethinkDB changeFeed cursor

Description

Allows you to be notified of changes to a file if the metadata property matches your object.

Example
bucket.watchMetadata({topic: 'cats'}).then(function (cursor) {
  cursor.each((err, catVideoChanges) => {
    console.log(catVideoChanges)
  })
})

deleteId(fileId)

Parameters
key default type description
fileId required String The id of the file to delete
returns

Returns a promise that resolves to a boolean, depending on whether the operation was successful.

Description

Marks a file as deleted in ReGrid

Example
bucket.deleteId('ca608825-15c0-44b5-9bef-3ccabf061bab')

renameId(fileId, filename)

Parameters
key default type description
fileId required String The id of the file to rename.
filename required String The new filename for the selected file.
returns

Returns a promise that resolves to a boolean, depending on whether the operation was successful.

Description

Renames a file in ReGrid

Example
bucket.renameId('ca608825-15c0-44b5-9bef-3ccabf061bab', 'newName.mp4')

getMetadata(fileId)

Parameters
key default type description
fileId required String The id of the file to read.
returns

Returns a promise that resolves to the file metadata.

Description

Retrieves the metadata for a given fileId.

Example
bucket.getMetadata('ca608825-15c0-44b5-9bef-3ccabf061bab')

replaceMetadata(fileId, metadata)

Parameters
key default type description
fileId required String The id of the file to rename.
metadata required Object The new metadata for the selected file.
returns

Returns a promise that resolves to a boolean, depending on whether the operation was successful.

Description

Replaces a file's metadata in ReGrid

Example
bucket.replaceMetadata('ca608825-15c0-44b5-9bef-3ccabf061bab', {topic: 'other cat stuff'})
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